/**
 * 缓动对象
 */
MPT.addObject('Tween', function(){
	
	var TweenType = {
		Linear: function(t,b,c,d){ return c*t/d + b; },
		Quad: {
			easeIn: function(t,b,c,d){
				return c*(t/=d)*t + b;
			},
			easeOut: function(t,b,c,d){
				return -c *(t/=d)*(t-2) + b;
			},
			easeInOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t + b;
				return -c/2 * ((--t)*(t-2) - 1) + b;
			}
		},
		Cubic: {
			easeIn: function(t,b,c,d){
				return c*(t/=d)*t*t + b;
			},
			easeOut: function(t,b,c,d){
				return c*((t=t/d-1)*t*t + 1) + b;
			},
			easeInOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t + b;
				return c/2*((t-=2)*t*t + 2) + b;
			}
		},
		Quart: {
			easeIn: function(t,b,c,d){
				return c*(t/=d)*t*t*t + b;
			},
			easeOut: function(t,b,c,d){
				return -c * ((t=t/d-1)*t*t*t - 1) + b;
			},
			easeInOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
				return -c/2 * ((t-=2)*t*t*t - 2) + b;
			}
		},
		Quint: {
			easeIn: function(t,b,c,d){
				return c*(t/=d)*t*t*t*t + b;
			},
			easeOut: function(t,b,c,d){
				return c*((t=t/d-1)*t*t*t*t + 1) + b;
			},
			easeInOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return c/2*t*t*t*t*t + b;
				return c/2*((t-=2)*t*t*t*t + 2) + b;
			}
		},
		Sine: {
			easeIn: function(t,b,c,d){
				return -c * Math.cos(t/d * (Math.PI/2)) + c + b;
			},
			easeOut: function(t,b,c,d){
				return c * Math.sin(t/d * (Math.PI/2)) + b;
			},
			easeInOut: function(t,b,c,d){
				return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
			}
		},
		Expo: {
			easeIn: function(t,b,c,d){
				return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
			},
			easeOut: function(t,b,c,d){
				return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
			},
			easeInOut: function(t,b,c,d){
				if (t==0) return b;
				if (t==d) return b+c;
				if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
				return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
			}
		},
		Circ: {
			easeIn: function(t,b,c,d){
				return -c * (Math.sqrt(1 - (t/=d)*t) - 1) + b;
			},
			easeOut: function(t,b,c,d){
				return c * Math.sqrt(1 - (t=t/d-1)*t) + b;
			},
			easeInOut: function(t,b,c,d){
				if ((t/=d/2) < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
				return c/2 * (Math.sqrt(1 - (t-=2)*t) + 1) + b;
			}
		},
		Elastic: {
			easeIn: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				return -(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
			},
			easeOut: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d)==1) return b+c;  if (!p) p=d*.3;
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				return (a*Math.pow(2,-10*t) * Math.sin( (t*d-s)*(2*Math.PI)/p ) + c + b);
			},
			easeInOut: function(t,b,c,d,a,p){
				if (t==0) return b;  if ((t/=d/2)==2) return b+c;  if (!p) p=d*(.3*1.5);
				if (!a || a < Math.abs(c)) { a=c; var s=p/4; }
				else var s = p/(2*Math.PI) * Math.asin (c/a);
				if (t < 1) return -.5*(a*Math.pow(2,10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )) + b;
				return a*Math.pow(2,-10*(t-=1)) * Math.sin( (t*d-s)*(2*Math.PI)/p )*.5 + c + b;
			}
		},
		Back: {
			easeIn: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158;
				return c*(t/=d)*t*((s+1)*t - s) + b;
			},
			easeOut: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158;
				return c*((t=t/d-1)*t*((s+1)*t + s) + 1) + b;
			},
			easeInOut: function(t,b,c,d,s){
				if (s == undefined) s = 1.70158; 
				if ((t/=d/2) < 1) return c/2*(t*t*(((s*=(1.525))+1)*t - s)) + b;
				return c/2*((t-=2)*t*(((s*=(1.525))+1)*t + s) + 2) + b;
			}
		},
		Bounce: {
			easeIn: function(t,b,c,d){
				return c - Tween.Bounce.easeOut(d-t, 0, c, d) + b;
			},
			easeOut: function(t,b,c,d){
				if ((t/=d) < (1/2.75)) {
				return c*(7.5625*t*t) + b;
				} else if (t < (2/2.75)) {
				return c*(7.5625*(t-=(1.5/2.75))*t + .75) + b;
				} else if (t < (2.5/2.75)) {
				return c*(7.5625*(t-=(2.25/2.75))*t + .9375) + b;
				} else {
				return c*(7.5625*(t-=(2.625/2.75))*t + .984375) + b;
				}
			},
			easeInOut: function(t,b,c,d){
				if (t < d/2) return Tween.Bounce.easeIn(t*2, 0, c, d) * .5 + b;
				else return Tween.Bounce.easeOut(t*2-d, 0, c, d) * .5 + c*.5 + b;
			}
		}
	};
	
	this.to = function(_elem, _type, _begin_prop, _diff_prop)
	{
		var tween_type_A = _type.split('.');
		var elem = _elem;
		var t=0, d=100;
		var timer = setInterval(function(){
			t++;
		
			if(_begin_prop['left']&&_diff_prop['left'])
			{
				var b = _begin_prop['left'];
				var c = _diff_prop['left'];
				elem.style.left = TweenType[tween_type_A[0]][tween_type_A[1]](t/*开始时间*/,b/*起始值*/,c/*差值*/,d/*持续时间*/) + "px";
			}
			
			if(_begin_prop['top']&&_diff_prop['top'])
			{
				var b = _begin_prop['top'];
				var c = _diff_prop['top'];
				elem.style.top = TweenType[tween_type_A[0]][tween_type_A[1]](t/*开始时间*/,b/*起始值*/,c/*差值*/,d/*持续时间*/) + "px";
			}
			
			if(_begin_prop['width']&&_diff_prop['width'])
			{
				var b = _begin_prop['width'];
				var c = _diff_prop['width'];
				elem.style.width = TweenType[tween_type_A[0]][tween_type_A[1]](t/*开始时间*/,b/*起始值*/,c/*差值*/,d/*持续时间*/) + "px";
			}
			
			if(_begin_prop['height']&&_diff_prop['height'])
			{
				var b = _begin_prop['height'];
				var c = _diff_prop['height'];
				elem.style.height = TweenType[tween_type_A[0]][tween_type_A[1]](t/*开始时间*/,b/*起始值*/,c/*差值*/,d/*持续时间*/) + "px";
			}
			
			if(t>d)
			{
				clearInterval(timer);
				timer=null;
			}
		}, 10);
	};
	
});
